KR20210024031A - Composition for aqueous coating solution containing polymer of N-vinylcarboxylic acid amide - Google Patents

Abstract

When producing a coated product from an aqueous composition containing a polymer of N-vinylcarboxylic acid amide, a configuration capable of efficiently drying is proposed. A composition for an aqueous coating liquid containing at least a polymer of N-vinylcarboxylic acid amide, a polysaccharide, and water.

Description

Composition for aqueous coating solution containing polymer of N-vinylcarboxylic acid amide

The present invention relates to a composition containing a polymer of N-vinylcarboxylic acid amide as a water-soluble polymer, and mainly includes a water-soluble polymer-containing paint, ink, adhesive, aqueous coating solution such as positive electrode, negative electrode, separator, etc. WHEREIN: It relates to the composition which can form an easy-drying coating material on the construction surface.

Coating and printing techniques using water-soluble polymers are starting to be widely used in the overall industrial field from the viewpoints and efficiency of environmental and safety aspects. In particular, in the case of thinning, the aqueous coating solution using a water-soluble polymer is very excellent, and the industrial advantage is very large.

Among them, polyN-vinylacetamide (hereinafter sometimes referred to as PNVA (registered trademark)), which is one of the polymers of N-vinylcarboxylic acid amide, has amphiphilic properties and is easy to achieve high molecular weight and high viscosity. From this point of view, it is used in various applications such as water-based inks and paints, thickening of various water-based compound coating solutions, film formation, and adhesives. In particular, they are used as adhesives, paints, building materials, and binder resins for secondary batteries in personal care fields such as pharmaceuticals and cosmetics, construction fields such as building materials, and industrial fields.

However, when a water-soluble polymer such as a polymer of N-vinylcarboxylic acid amide is dissolved in water and used as a solvent, the drying efficiency is greater than when using an organic solvent, except for some organic solvents having a high boiling point. It often falls.

In addition, in applications where film properties are not expected, a non-hydrophilic polymer emulsion or rubber latex may be used as an aqueous coating solution. There was also a problem with this taking. Polymer emulsions and rubber latex have many problems in that thickening cannot be expected as a coating binder and the coating surface is soft.

In general, improving the drying efficiency is often addressed by improving the equipment or making the drying conditions appropriate.

The improvement of equipment is naturally limited in that the cost is often enormous, and the influence on the object to be dried is not small to increase the hot air temperature or air volume.

In addition, in terms of energy saving, it is necessary to avoid unnecessary increase in energy consumption due to an increase in drying temperature or air volume.

In particular, in manufacturing a secondary battery such as a lithium ion battery, a thin film of the coated material is required from the viewpoint of weight reduction and high density. For this reason, the direction in which energy consumption in the manufacturing process is increased is very undesirable considering environmental considerations, and it is recognized as a necessary technique to increase the drying speed of a coated article containing a water-soluble polymer.

There are the following as the prior art related to the improvement of the water-based coating liquid drying method.

For example, in Patent Document 1, it is a drying method in which a coating solution is irradiated with near-infrared rays from a short distance of 10 to 35 cm and blown to cure the coating material. This is an improvement in drying conditions, not an improvement in drying properties of the binder itself.

In addition, as a method for improving the drying property of a water medium substance, it is also conceivable to add inorganic fillers or non-hydrophilic resins to the emulsion, but it is not necessarily applicable to a coating liquid containing a water-soluble polymer.

For example, Patent Document 2 describes a composition in which talc is added to water-dispersible emulsions as a cement-based base control material, but is intended for drying by natural drying or air drying, and coating containing a water-soluble polymer The application range is quite limited as a method for improving the drying properties of the liquid.

In addition, in Patent Document 3, an adhesive composition containing a thermoplastic resin powder such as an acrylic resin in an aqueous resin dispersion comprising a styrene-butadiene copolymer latex and a chloroprene rubber latex is disclosed. However, in the case of using a water-soluble polymer, it is often difficult to add a water-insoluble substance, and the range of application is extremely narrow in that the amount of addition is also limited.

Patent Document 4 discloses a thickening dispersant for a slurry for a positive electrode of a lithium ion secondary battery containing at least one type of water-soluble polymer such as carboxymethylcellulose and polyN-vinylacetamide. However, as a result of enhancing the binding properties between the positive electrode active materials and between the positive electrode active material and the current collector, the concentration of the thickening dispersant in the positive electrode slurry is low, and there is neither disclosure nor suggestion of the subject of drying.

Japanese Patent Application Publication No. Hei 6-170327 Japanese Patent No. 5543149 Japanese Patent Publication No. 2009-102606 WO2015/146649 publication

In general, in the case of improving the drying property of a coating liquid containing a water-soluble polymer, there are few cases where it is possible to add a non-hydrophilic resin or the like to the composition in the first place, and there are many cases where there are quantitative restrictions when it can be added. There are never many cases that can make use of its effectiveness.

When preparing a coated article from an aqueous composition in which a polymer of N-vinylcarboxylic acid amide is dissolved, there is no suggestion of a constitution capable of efficiently drying.

Under such circumstances, as a result of intensive investigation, the present inventors found that drying properties were remarkably improved by mixing a polymer of N-vinylcarboxylic acid amide, which is a water-soluble polymer, and a polysaccharide, and came to complete the present invention.

That is, the configuration of the present invention is as follows.

[1] A composition for an aqueous coating liquid containing at least a polymer of N-vinylcarboxylic acid amide, a polysaccharide, and water.

[2] The composition for an aqueous coating solution according to [1], wherein the N-vinylcarboxylic acid amide is N-vinyl acetamide.

[3] The composition for an aqueous coating solution according to [1], wherein the polysaccharide is a cellulose derivative.

[4] The composition for an aqueous coating solution according to [3], wherein the cellulose derivative is an alkali (earth) metal salt of carboxymethylcellulose.

[5] The composition for an aqueous coating solution according to [1] to [4], wherein the composition ratio of the polymer of the N-vinylcarboxylic acid amide and the polysaccharide is 95:5 to 50:50 by mass ratio.

[6] The composition for aqueous coating solutions of [1] to [5], further containing inorganic fillers.

[7] The composition for an aqueous coating liquid according to [6], wherein the inorganic fillers are alumina.

[8] The composition for aqueous coating solutions of [1] to [7], wherein the content of the polymer of N-vinylcarboxylic acid amide in the composition is in a range of 0.05 to 20% by mass.

[9] A method for producing a water-based polymer coated article, wherein the composition for an aqueous coating liquid of [1] to [8] is applied and dried on the surface of a substrate.

According to the present invention, since the polysaccharide is contained in the composition containing the polymer of water and N-vinylcarboxylic acid amide, the drying property is remarkably improved when the composition is coated.

The composition of the present invention has a structure derived from N-vinylcarboxylic acid amide, has high hydrophilicity in that it retains polarity, and has a wetting, dispersing, and thickening action for various aqueous solutions, etc. Has adhesiveness. Among them, the affinity to metal, glass, polypropylene, polyethylene, polyethylene terephthalate film, and the like is extremely high, and adhesion to these materials is also high.

Such a composition is suitably used in fields requiring wetting, dispersing and thickening effects, adhesion effects, and the like. In particular, it can be used as an adhesive, a paint, a building material, and a coating liquid for secondary batteries in the field of personal care such as medicine and cosmetics, or in the field of construction and industry such as building materials.

Hereinafter, the present invention will be described in detail. The configuration of the present invention is, of course, not limited to these.

Composition for aqueous coating solution

The composition for aqueous coating liquid of the present invention contains at least water, a polymer of N-vinylcarboxylic acid amide, and a polysaccharide as an essential composition. Examples of the coating liquid include adhesives, paints, ink, and positive electrodes, negative electrodes, and separators of lithium ion batteries. Hereinafter, each component is demonstrated.

Polymer of N-vinylcarboxylic acid amide

In the present invention, a polymer of N-vinylcarboxylic acid amide is used as the water-soluble polymer.

N-vinylcarboxylic acid amide is represented by the following formula (1).

(In General Formula (1), R ¹ is any one selected from the group ^{consisting of a hydrogen atom and a hydrocarbon group having 1 to 6 carbon atoms. R 2} represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. R ¹ is NR ² and may form a ring structure)

As N-vinylcarboxylic acid amide, specific examples include N-vinylformamide, N-vinylacetamide, N-vinylpropionamide, N-vinylbenzamide, N-vinyl-N-methylformamide, and N-vinyl -N-ethylformamide, N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide, N-vinylpyrrolidone, and the like. Among these, N-vinylacetamide is particularly preferred. N-vinylcarboxylic acid amide may be used singly or in combination of two or more.

The polymer used in the present invention may be a homopolymer of N-vinylcarboxylic acid amide, but may be a copolymer containing other monomer units in the structure.

The other monomer unit is not particularly limited as long as it is copolymerizable with N-vinylcarboxylic acid amide, and for example, methacrylic acid, itanic acid, maleic acid, maleic anhydride, crotonic acid, and salts or esters that are derivatives thereof Unsaturated carboxylic acid monomers such as;

Acryloylmorpholine, isopropylacrylamide;

Unsaturated nitrile monomers such as metachloronitrile and α-chloroacrylonitrile;

Methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, pentyl (meth) acrylate, heptyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl ( Linear or branched alkyl group-containing ethylenically unsaturated monomers such as meth)acrylate and tetradecyl (meth)acrylate;

Alicyclic alkyl group-containing ethylenically unsaturated monomers such as cyclohexyl (meth)acrylate and isobornyl (meth)acrylate;

Fluorinated alkyl group-containing ethylenically unsaturated monomers such as trifluoroethyl (meth)acrylate and heptadecafluorodecyl (meth)acrylate; (Meth)acrylamide, N-methoxymethyl-(meth)acrylamide, N-ethoxymethyl-(meth)acrylamide, N-propoxymethyl-(meth)acrylamide, N-butoxymethyl-(meth) )Acrylamide, N-pentoxymethyl-(meth)acrylamide, N,N-di(methoxymethyl)acrylamide, N-ethoxymethyl-N-methoxymethylmethacrylamide, N,N-di( Ethoxymethyl)acrylamide, N-ethoxymethyl-N-propoxymethylmethacrylamide, N,N-di(propoxymethyl)acrylamide, N-butoxymethyl-N-(propoxymethyl)methacryl Amide, N,N-di(butoxymethyl)acrylamide, N-butoxymethyl-N-(methoxymethyl)methacrylamide, N,N-di(pentoxymethyl)acrylamide, N-methoxymethyl -N-(pentoxymethyl)methacrylamide, N,N-dimethylaminopropylacrylamide, N,N-diethylaminopropylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, etc. Amide group-containing ethylenically unsaturated monomer of;

2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycerol mono (meth)acrylate, 4-hydroxyvinylbenzene, 1- Hydroxyl group-containing ethylenically unsaturated monomers such as ethynyl-1-cyclohexanol and allyl alcohol; Styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, vinylnaphthalene, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, phenoxydiethylene Glycol acrylate, phenoxy diethylene glycol methacrylate, phenoxy tetraethylene glycol acrylate, phenoxy tetraethylene glycol methacrylate, phenoxy hexaethylene glycol acrylate, phenoxy hexaethylene glycol methacrylate, phenyl acrylate, Phenyl methacrylate, etc.,

When crosslinking is required, methacrylic acid 2-[(O-1'-methylpropylideneamino)carboxyamino]ethyl (Carenz MOI-BM (registered trademark) manufactured by Showa Denko Co., Ltd.), and 2-[ (3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate (Carenz MOI-BP (registered trademark) manufactured by Showa Denko Corporation), dihydroxypropyl (meth)acrylate, Kyoeisha Chemical name light ester HO, copper HOP, copper HOB, copper HOA, copper HOPA manufactured by Chemical Co., Ltd. Trade name light acrylate (registered trademark) manufactured by Chemical Industry Co., Ltd. Monomer units derived from HOBA are mentioned. have.

It is preferable that the content of the monomer unit derived from N-vinylcarboxylic acid amide in the copolymer is 60 mol% or more and 100 mol% or less.

Among them, the homopolymer of N-vinylacetamide is excellent in forming a thin film when applying the aqueous solution blending agent to various substrates, and from the viewpoint of heat resistance, it is most preferable as a coating material for secondary batteries having a high level of safety requirements.

The weight average molecular weight of the polymer of N-vinylcarboxylic acid amide used in the present invention is preferably 10,000 to 4 million, more preferably 100,000 to 3 million, and even more preferably 500,000 to 200. It is in the range of the bay. The weight average molecular weight here is determined by the method by the GPC measurement method mentioned later.

In addition, the viscosity is that the viscosity of the aqueous solution in which the polymer is dissolved in water at 5% by mass is preferably 1,000 to 30,000 mPa·s, more preferably 3,000 to 20,000 mPa·s, and even more preferably 6,000 to 20,000 mPa·s. It is 15,000mPa·s. The viscosity was determined by a Brookfield viscometer described later.

An aqueous solution of a polymer having such properties becomes a viscous liquid having thixotropy and slipperiness.

The method for producing the polymer is not particularly limited, and it can be produced by polymerizing various monomers of N-vinylcarboxylic acid amide by a known polymerization method using a radical polymerization initiator. As a polymerization method, a solution polymerization method, an aqueous solution polymerization method, a precipitation precipitation polymerization method, and a reverse layer suspension polymerization method are mentioned, for example. Upon completion of the polymerization, a viscous liquid, agar, or powdery product is obtained. In addition, viscous liquid and agar products can be powdered by dehydrating and drying.

In the case of applying for a coating application, a radical polymerization method in an aqueous solution is preferred because high molecular weight is essential.

When the polymerization reaction is carried out by an aqueous solution polymerization method, an aqueous monomer solution is put in a reaction tank equipped with a stirrer, a thermometer, and a nitrogen gas vent pipe, and the aqueous monomer solution is aerated with nitrogen gas. Subsequently, when a radical polymerization initiator is added and mixed, polymerization is started. This aqueous monomer solution is obtained by dissolving various monomers such as N-vinylcarboxylic acid amide and an unsaturated carboxylic acid monomer in ion-exchanged water in advance and adjusting the polymerization initiation temperature. The introduction temperature of the radical polymerization initiator is preferably 45 to 70°C, and may be produced by sequential polymerization in which an aqueous monomer solution or an aqueous polymerization initiator solution is added dropwise.

In the case of the polymerization method in which all the monomers are added in advance, the temperature inside the polymerization tank rises to a peak temperature by about 0.5 to 3 hours after the initiator is added.

The concentration of the N-vinylcarboxylic acid amide monomer in the aqueous monomer solution is usually preferably 3 to 20% by mass, more preferably 5 to 15% by mass, even more preferably 7 to 12% by mass, and the monomer in the aqueous monomer solution When the concentration is in this range, the polymerization rate and the degree of exotherm are suitable, so that the target viscosity is obtained, and can be easily taken out from the reaction tank.

As the polymerization initiator used for polymerization of N-vinylcarboxylic acid amide, those generally used for radical polymerization of vinyl compounds can be used without limitation. For example, a redox type polymerization initiator, an azo compound type polymerization initiator, and a peroxide type polymerization initiator are mentioned.

These may be used individually by 1 type, and may use 2 or more types together. In some cases, molecular weight adjustment may be performed using a chain transfer agent.

Examples of the redox polymerization initiator include combinations of ammonium persulfate and sodium thiosulfate, sodium hydrogen thiosulfate, trimethylamine, or tetramethylethylenediamine, or combinations of t-butyl hydroperoxide and sodium thiosulfate or sodium hydrogen thiosulfate. I can.

Examples of the peroxide polymerization initiator include persulfates such as sodium, potassium and ammonium, organic peroxides such as benzoyl peroxide, lauroyl peroxide, caproyl peroxide, t-butylperoctoate, and diacetyl peroxide.

Examples of azo-based initiators include 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2'-azobis(iso Butyrate), dimethyl-2,2'-azobis (2-methylbutyrate) and dimethyl-2,2'-azobis (2,4-dimethylpentanoate, 2,2'-azobis (2-amidino Propane) dihydrochloride, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]n hydrate, 2,2'-azobis {2-[N-(2-carboxyethyl) Azo compounds, such as) amidino]propane}n hydrate and 2,2'-azobis(2-methylpropionic acid)dimethyl, etc. are mentioned.

Among the above polymerization initiators, in the polymerization method using water as a solvent, considering the effect of the residue on the polymer, 2,2'-azobis[N-(carboxyethyl)-2-methylpropionami It is most preferable to use din]tetrahydrate (trade name: azo polymerization initiator VA-057 manufactured by Fujifilm Wako Junyaku Co., Ltd.).

This VA-057 is dissolved in water degassed with nitrogen gas and used.

These radical polymerization initiators may be used in combination, or polymerization is possible even if they are used in combination with a redox polymerization initiator and a water-soluble azo compound polymerization initiator.

In that case, it is preferable to use a combination of ammonium persulfate and sodium thiosulfate as a redox-based polymerization initiator, and 2,2'-azobis(2-amidinopropane) dihydrochloride as a water-soluble azo compound-based polymerization initiator.

The amount of the radical polymerization initiator to be used is preferably 100 to 10000 ppm by mass, more preferably 500 to 5000 ppm by mass, in the case of an azo compound polymerization initiator, based on the total amount of all monomers, and in the case of a redox polymerization initiator It is preferably 10 to 300 ppm by mass, more preferably 30 to 100 ppm by mass. When the amount of the radical polymerization initiator is within the above range, both the polymerization rate and the molecular weight of the copolymer are likely to be suitable.

As long as the object of the present invention is not impaired, even if a chain transfer agent is used during polymerization for the purpose of controlling the degree of polymerization of the polymer or for introducing a modifying group at the end of the polymer, there is no problem. Examples of the chain transfer agent include aldehyde compounds such as propionaldehyde, ketone compounds such as acetone and methyl ethyl ketone, thiol compounds such as 2-hydroxyethanethiol, 3-mercaptopropionic acid, dodecanethiol, and thioacetic acid, and carbon tetrachloride, And halogenated hydrocarbon compounds such as trichloroethylene and tetrachloroethylene, and phosphinates such as sodium phosphinate monohydrate. Among these, thiol compounds, aldehyde compounds, and ketone compounds are suitably used. The addition amount of the chain transfer agent is preferably 0.1% by mass or more and 2.0% by mass or less with respect to the total amount of all monomers. If it is in this range, objectives such as control of the degree of polymerization and introduction of a modifying group at the terminal of the polymer can be sufficiently performed.

Polysaccharide

The polysaccharide is not particularly limited as long as it is hydrophilic, and xanthan gum, gellan gum, pectin, carrageenan, guar gum, karaya gum, dextrin, cellulose derivatives, and the like can be used. Among these, a cellulose derivative is preferable from the viewpoint of high heat resistance.

Also about the cellulose derivative, the following can be used without being specifically limited. Specifically, methylcellulose, hydroxypropylmethylcellulose, alkali (earth) metal salts of carboxymethylcellulose, hydroxyethylcellulose, hydroxyethylmethylcellulose, and the like can be used. As the alkali (earth) metal salt, sodium salt, potassium salt, lithium salt, magnesium salt, calcium salt and the like are used.

water

The water is not particularly limited, and distilled water, ion-exchanged water, tap water, or the like can be used, but ion-exchanged water is preferable.

Composition for aqueous coating solution

The composition for an aqueous coating solution of the present invention is a composition obtained by dissolving a polymer of the N-vinylcarboxylic acid amide and a polysaccharide in a solvent containing at least water.

The method of mixing the polymerization product of N-vinylcarboxylic acid amide and the polysaccharide is not particularly limited, but in order to obtain a more uniform mixture, the polymerization product of N-vinylcarboxylic acid amide and the polysaccharide are used as a solvent containing at least water. After dissolving in, it is preferable to mix with other compounding agents as needed. Further, more preferably, it is preferable to dissolve both the polymer of N-vinylcarboxylic acid amide and the polysaccharide in a solvent containing at least water, followed by mixing and homogenizing. This makes it possible to take the ideal mixing form. Water is used as the solvent, but a mixed solvent in which water and alcohols are mixed may be used. When mixing alcohols, it is contained in the solvent in an amount of preferably 50% by mass or less. It is preferable to use only water from the viewpoints of cost, manufacturing management, waste treatment, and the like.

The ideal mixture is a state in which polysaccharides such as cellulose derivatives are finely dispersed in a water-soluble polymer, which is a polymer of N-vinylcarboxylic acid amide, and inhibits some of the hydrogen bonds between the polymer of N-vinylcarboxylic acid amide and water. As a result of presumption, it is thought that water becomes easy to dissociate and becomes easy to dry.

In order to obtain the effect, an effect can be expected if the amount of one of them is less than that of the mixed state at the same ratio, and in the present invention, the effect is expressed when the polysaccharide is less than the polymer of N-vinylcarboxylic acid amide. easy.

As for the ratio of the polymerization product of N-vinylcarboxylic acid amide to the polysaccharide, from the above reasons, it is not said that it is better as the ratio of the polysaccharide increases, and the mixing ratio of the water-soluble polymer and the polysaccharide is the mass ratio (N-vinylcarboxylic acid The polymer of amide: polysaccharide) is preferably 95:5 to 30:70, more preferably 95:5 to 50:50, and even more preferably 90:10 to 80:20. In addition, the mixing ratio corresponds to the composition ratio.

If it is in this range, a composition excellent in easiness of drying can be obtained. In addition, "ease of drying" means that, for example, when the same amount of heat is added, drying can be performed in a time shorter than the drying time of the polymer of N-vinylcarboxylic acid amide. If the drying time is short, the time to apply heat is less, and the time until tableware can be shortened. For this reason, it is possible to reduce the heat history of the substrate or the like.

The concentration of the polymerized product of N-vinylcarboxylic acid amide in the composition is appropriately selected depending on the application in which the composition is used, the coating method, the viscosity of the coating liquid, etc., but is usually based on the total weight of the composition containing a solvent containing at least water On the other hand, it is preferably in the range of 1 to 30% by mass, more preferably 2 to 20% by mass, and even more preferably 4 to 15% by mass. If it is in this range, coating can be performed by a known printing means, and drying can be performed quickly.

The content of polysaccharides in the composition is appropriately selected depending on the application in which the composition is used, the coating method, the viscosity of the coating liquid, etc., but usually, preferably 0.05% by mass with respect to the total weight of the composition containing a solvent containing at least water. It is preferably in the range of 10% by mass or less, more preferably 0.1% by mass or more and 5% by mass or less, and even more preferably 0.2% by mass or more and 3% by mass or less. If it is in this range, it can exert an effect in accelerating drying of a composition.

Further, the composition according to the present invention may contain inorganic fillers. When the inorganic filler is included, the surface area increases and the filler itself has heat dissipation properties, so that drying properties can be further improved. For a composition to which an inorganic filler is added, the coating material itself has high heat dissipation, heat resistance, and toughness, so that the industrial advantage is very large.

As the inorganic filler, at least one selected from the group consisting of boron nitride, aluminum nitride, silicon carbide, silica, alumina, boehmite, talc, zinc oxide, titanium oxide, titanium black, and graphite can be used. In terms of heat dissipation and availability, alumina is preferred.

The content of the inorganic fillers is preferably in the range of 70% by mass or less, more preferably 20 to 60% by mass, and even more preferably 30 to 55% by mass based on the total weight of the composition. If it is in this range, it can exert an effect in accelerating drying of a composition.

In the method for producing a water-based polymer coating material according to the present invention, a coating material is prepared by applying the composition for an aqueous coating solution to a surface of a substrate and drying it to form a coating film. The composition is as described above.

In other words, in the present invention, a coating/drying method of significantly shortening the drying time compared to a composition not containing polysaccharides by mixing a predetermined amount of polysaccharides in a composition containing at least water of a polymer of N-vinylcarboxylic acid amide. Can provide.

Although it does not specifically limit as a coating method for the base material of a composition, In addition to a spray coat, a roll coat, a bar coat, a gravure coat, a die coat, a knife coat, an inkjet coat, a brush application, an immersion application, etc., a roll-to-roll pattern application device It is also possible to coat continuously by using.

In addition, the composition may contain a known material added to the paint other than the above, and may contain, for example, an emulsion-based binder, a thixotropic agent, a dispersant, a surface modifier, an antifoaming agent, and a leveling agent.

As the substrate, a film, a nonwoven fabric, a porous body, a plate body, etc. can be used without particular limitation.

Materials constituting the substrate include homopolypropylene, copolymers of propylene and other olefins, polyethylene terephthalate, polyethylene naphthalate, polyamide ether ketone, polyimide, polyamide, polyphenylene sulfone, polyphenylene ether, polyethylene, Organic resin materials such as polyethersulfone, polyetheretherketone, polybenzoimidazole, polyetherimide, polyamideimide, poly(p-phenylene2,6-benzobisoxazole), fluororesin, epoxy resin, aluminum , Metal materials such as copper, silver, and iron, glass (silicon oxide), alumina, magnesia, aluminum nitride, aluminum carbide, silicon nitride, barium titanate, and the like. The substrate may be used singly or in combination of two or more.

The drying method is not particularly limited, and is not particularly limited, such as spin drying, vacuum drying, warm air drying, infrared drying, and the like.

The drying time is also not particularly limited, but according to the present invention, compared to the case of drying the N-vinylacetamide polymer alone, the drying time is reduced in a ratio of 1/3 to 1/10 at the 95% by mass drying time described later. It can be shortened.

Example

Hereinafter, the present invention will be described by way of examples, but the present invention is not interpreted to be limited thereto.

[Production Example]

Polymerization of N-vinylacetamide

A nitrogen gas vent pipe, stirrer, solvent dropping device, and thermometer were attached to a 4-neck 1-liter separable flask, and 550 g of ion-exchanged water was added to the separable flask, followed by N-vinylacetamide (Showa Denko Corporation). Co., Ltd.) 50g was added. In that state, while performing nitrogen gas substitution in the dissolved solution, the mixture was heated with stirring to raise the polymerization initiation temperature to 51°C, and the initiator 2,2'-azobis[N-(carboxyethyl)-2-methylpropionamidine]tetrahydrate ( Hereinafter, 0.04 g (0.08 mass% of total monomer ratio) of VA-057) was dissolved in 10 g of ion-exchanged water subjected to nitrogen gas degassing. In that state, the polymerization reaction was allowed to proceed for 4 hours, and after that, the internal temperature was raised to 80°C and the sample was held for 1 hour, and the residual monomer was measured by HPLC method, and the reaction was performed when the monomer became 1000 mass ppm or less. After that, 400 g of ion-exchanged water was added, diluted, and stirred for 1 hour, followed by cooling.

Moreover, the weight average molecular weight of the obtained N-vinylacetamide polymer was 2,000,000. Further, the viscosity of the 5% by mass aqueous solution was 11,500 mPa·s.

Measurement of weight average molecular weight

The polymer was dissolved in distilled water at a concentration of 1% by mass, and the weight average molecular weight was measured by GPC (gel permeation chromatography) under the following conditions.

In addition, for the calculation of the weight average molecular weight in this measurement, a calibration curve created from the absolute molecular weight measurement result of the N-vinylacetamide polymer in each molecular weight range was used.

Detector (RI): SHODEX (registered trademark) manufactured by Showa Denko Corporation RI-201H Pump: LC-20AD manufactured by Shimadzu Corporation

Column oven: SHODEX (registered trademark) AO-30C manufactured by Showa Denko Co., Ltd.

Analysis device: SIC 480Ⅱ Deta Station manufactured by System Instruments Co., Ltd.

Column: SHODEX (registered trademark) SB806 x 2 manufactured by Showa Denko Co., Ltd.

Eluent: distilled water/2-propanol=8/2 (mass ratio)

Flow: 0.7 ml/min

Viscosity measurement method

Put the test body in a 300ml tall beaker and settled in a thermostat at 20°C for 12 hours or longer, so that there are no internal air bubbles. After that, put a beaker in a constant temperature water bath adjusted to 20°C, and confirm that the temperature of the specimen is 20±0.5°C with a thermometer, and measure the viscosity under the following conditions using a B-type viscometer shown in JIS K-7117-1-1999. Measure. The viscosity is recorded 10 minutes after the value has stabilized.

Viscometer: DVE (Brookfield) viscometer type HA

Spindle: No.6 spindle

RPM: 50rpm

Temperature: 20℃

Measurement of residual monomer amount

A polymer sample was dissolved in an aqueous solution _{of sodium sulfate (Na 2} SO ₄ ) having a concentration of 0.05 mol/L to obtain a polymer solution. The concentration of the polymer in this polymer solution is 0.1% by mass. Then, this polymer solution was analyzed by the GPC method to calculate the total amount of various monomers remaining in the polymer sample (the amount of residual monomers). It is possible to confirm whether the polymerization reaction has been completed or not by the amount of the residual monomer.

Detector (RI): SHODEX (registered trademark) UV-41 manufactured by Showa Denko Corporation

Pump: SHODEX (registered trademark) DS-4 manufactured by Showa Denko Corporation

Column oven: U-620 40° C. manufactured by Sugai

Analysis device: C-R7A Plus manufactured by Shimadzu Corporation

Column: Showa Denko Co., Ltd. SHODEX (registered trademark) SB802.5HQ x 1

Eluent: 0.05 mol/L Na ₂ SO ₄ aqueous solution flow rate 1.0 ml/min

The concentration was calculated|required by the calibration curve method (sample concentration: 1, 5, 10, 100 mass ppm).

[Examples 1 to 16]

An aqueous solution of a polymer of 5% by mass of N-vinylacetamide obtained in Preparation Example and an aqueous solution of 5% by mass concentration as a polysaccharide shown in Table 1 were stirred and homogenized in the same container at 25°C according to the mixing ratio of Table 1 to obtain aqueous solution. A composition for coating liquid was prepared. Further, in Example 16, after homogenization, alumina was mixed in the ratio shown in Table 1.

[Comparative Examples 1 to 7]

A composition for aqueous coating solutions having the composition shown in Table 1 was prepared. In addition, in Comparative Example 7, alumina was mixed with the aqueous solution of Comparative Example 1 in the ratio shown in Table 1.

In addition, materials other than the polymer of N-vinylacetamide (PNVA) used in Examples and Comparative Examples are as follows.

Sodium salt of carboxymethylcellulose (CMC): MAC-350-HC Nippon Seishi Co., Ltd.

Acrylic emulsion: Viniblan (registered trademark) 2685 Nisshin Chemical Industry Co., Ltd.

Styrene Butadiene Latex: BM-400B Nippon Xeon Co., Ltd.

Guar gum: manufactured by Junsei Chemical Co., Ltd.

Hydroxyethylcellulose (HEC): AW-15F manufactured by Sumitomo Seika Co., Ltd.

Alumina: AL-160SG Showa Denko Co., Ltd.

The drying rate was measured by the following method.

Evaluation (95% by mass drying time and 47.5% by mass drying time)

Take 1.5 g of the composition for aqueous coating solution of the sample on an aluminum cup and place it, and spread it evenly and evenly on the bottom of the aluminum cup with a spoon. For the samples of Examples 1 to 15 and Comparative Examples 1 to 6, with a thermal balance (manufactured by METTLER TOLEDO Co., Ltd.: PM460), 95% by mass decrease from the original mass at 85°C, that is, water almost evaporates. The evaporation time to is measured at 1 minute intervals.

For Examples 1 to 15, the evaporation time difference (shortened time) from Comparative Example 1 in which no polysaccharide was added was calculated.

For Example 16 and Comparative Example 7, the evaporation time from the original mass to 47.5% by mass was evaluated at 85°C. In Example 16, the difference in evaporation time from Comparative Example 7 was taken as the shortening time.

Table 1 shows the results.

From the results of Table 1, even when compared with an acrylic emulsion or styrene butadiene latex having a high drying rate, polysaccharides such as CMC were added to and mixed with the polymer of N-vinylacetamide, thereby showing an inferior drying time. In addition, it can be seen that the drying property is most improved when the ratio of the polysaccharide to the polymer of N-vinyl acetamide is about 10 to 20% by mass.

In addition, the drying speed is faster depending on the ratio in the case of mixing the N-vinylacetamide polymer and the polysaccharide than in the case of containing the polysaccharide alone, which does not contain the N-vinylcarboxylic acid amide polymer, and the inorganic filler. Also in the system to which the polysaccharide is added, the drying rate is faster in the system to which the polysaccharide is added, and the mixing of the polymer of N-vinyl acetamide and the polysaccharide can be said to be a useful means for accelerating the drying rate.

As described above, the drying speed can be increased by adding and mixing polysaccharides such as CMC in a constant ratio to the polymer of N-vinylcarboxylic acid amide.

In the manufacture of products having a process of coating and drying an aqueous coating liquid containing a polymer of N-vinylcarboxylic acid amide, according to the present invention, it is possible to dry at a higher speed, which will greatly contribute to the improvement of productivity in the entire industry. It is expected.

Claims (9)

A composition for an aqueous coating liquid containing at least a polymer of N-vinylcarboxylic acid amide, a polysaccharide, and water. The method of claim 1,
The composition for an aqueous coating solution, wherein the N-vinylcarboxylic acid amide is N-vinylacetamide. The method of claim 1,
The composition for an aqueous coating solution, wherein the polysaccharide is a cellulose derivative. The method of claim 3,
The composition for an aqueous coating solution, wherein the cellulose derivative is an alkali (earth) metal salt of carboxymethylcellulose. The method according to any one of claims 1 to 4,
The composition for an aqueous coating solution, wherein the composition ratio of the polymer of the N-vinylcarboxylic acid amide and the polysaccharide is 95:5 to 50:50 in a mass ratio. The method according to any one of claims 1 to 5,
Further, a composition for aqueous coating solutions containing inorganic fillers. The method of claim 6,
The composition for an aqueous coating solution, wherein the inorganic fillers are alumina. The method according to any one of claims 1 to 7,
The composition for an aqueous coating solution, wherein the content of the polymer of N-vinylcarboxylic acid amide in the composition is in a range of 0.05 to 20% by mass. Applying and drying the composition for an aqueous coating solution according to any one of claims 1 to 8 on the surface of a substrate,
A method for producing an aqueous polymer coating.